SDV FAQ

The number of cablecard models probably peaked in 2006. If you do a search for cable card at the best buy site, you get zero results, Circuit city: 2 (1 is the THD), you get a few more at Crutchfield, mostly large Mitsubishis. A lot of TV sets offer clear QAM, which would be more useful if cable companies actually populated their PSIP tables correctly. Most manufacturers have given up on cablecard 1.

I know that when I bought my 2006 Samsung, it was the first model year after they had decided that CableCARD was an elite feature, and restricted it to only the top-level model (5088), not providing it on their other models (5086, 5087, 5066, 5067).

The CE OEMs gave up on CableCARD V1 because of very poor support for the technology by cable providers and cable's successful campaign to discourage their use by their subs. Of the millions of units which were sold with CableCARD slots, the cable industry industry claims that only a few hundred thousand have been used.

The cable industry itself is pushing support for interactive "CableCARD" (they're working feverishly to get rid of the cards), but the interactive stuff that they want iis expensive to support in a product, restricting its inclusion to high-end models. The CE OEMs have been lobbying for a simpler standard to support a fixed set of services (IPG, IPPV, VOD, SDV) which can be included in cheaper products; cable's response has been that cheap products don't need IPG, IPPV and VOD and for SDV, we'll give you the Tuning Adapter. Including a unidirectional CableCARD interface and a USB port in a product won't add much to its price today (TiVo includes two CableCARD slots and two USB ports in a $300 box, albeit one whose price is heavily subsidized by service contracts), and the FCC requires that nearly all television products have the ability to tune ATSC and therefore to handle decoding and imaging a reasonably high-rate MPEG-2 stream.

The number of cablecard models probably peaked in 2006. If you do a search for cable card at the best buy site, you get zero results, Circuit city: 2 (1 is the THD), you get a few more at Crutchfield, mostly large Mitsubishis. A lot of TV sets offer clear QAM, which would be more useful if cable companies actually populated their PSIP tables correctly. Most manufacturers have given up on cablecard 1.

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Yep this is what my Sony Bravia XBR4 does (and something I wish the HD TiVo DVRs did). It works well with local broadcast channels sent via cable since the PSIP data is set correctly for them. For cable channels though it's worthless since a) cable companies don't set up PSIP for cable channels and b) 99% of the cable channels are encrypted so they can't be tuned anyway.

I just noticed that in the CableLabs certification list of devices, there is now an additional column entitled Tuning Adapter Capable and only the Tivo THD & S3 devices have Yes in that column. I guess that means the Tivo devices now are officially certified as Tuning Adapter Capable thus clearing another milestone for general release.http://www.cablelabs.com/udcp/downloads/OC_PNP.pdf

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What really chops my nards is the fact the USB based adapter was the most inferior of the most likely ways to implement the adapter, but it was promoted in favor of an Ethernet based solution because, "an Ethernet based solution would only serve TiVos, and none of the other existing UDCPs". The fact is, however, even a USB based adapter is only going to be supported on the TiVo. The fact many other existing UDCP products have USB ports is irrelevant, because having the USB port in no way means they have the infrastructure to support a Tuning Adapter. For new designs, the port type is not really relevant, as it is no more difficult to add an Ethernet port to a TV than a USB port. For the average consumer, however, it means they will need one TA for every UDCP, whereas the Ethernet solution could easily have serviced the entire house with a single TA. It also means the TA is going to have to sit near the UDCP it services, rather than in a closet or computer room somewhere. Most people are not enamored of additional clutter in their living rooms from additional boxes and the cables attached to them.

It appears possible, or even likely now, the CATV companies may be offering the TA free, but I wonder if they will provide three of them free? I also wonder if they might change their mind a year from now and start charging a monthly fee for the TA? It certainly would not be the first time a CATV company flip-flopped on providing a service free and then later charging for it.

But at least it can be stuffed back out of sight somewhere, since it doesn't have an IR port or display that the user has to interact with.

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You are assuming there is room behind the components to stuff it back out of sight. In the case of my living room, there isn't. Not only that, but for me it isn't the visibility that is an issue. I don't care if I can see the box, or not. The issue is getting to the box to service it.

You are assuming there is room behind the components to stuff it back out of sight. In the case of my living room, there isn't. Not only that, but for me it isn't the visibility that is an issue. I don't care if I can see the box, or not. The issue is getting to the box to service it.

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In my case, I don't have a place to "stuff" the box, nor do I want to go crazy when/if I have to service it.

An ethernet interface would be a bit more complex, especially to make it secure, plus ethernet is already used for TiVos networking (or at least could be). Plus the TA is probably intended as one unit per UDCP, not one per home. TiVo has at least one USB port clear anyway, so is just as easy, if not easier than ethernet.

A properly designed HT setup will allow for hiding the device someplave, and having it available for servicing.

An ethernet interface would be a bit more complex, especially to make it secure, plus ethernet is already used for TiVos networking (or at least could be). Plus the TA is probably intended as one unit per UDCP, not one per home. TiVo has at least one USB port clear anyway, so is just as easy, if not easier than ethernet.

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Ethernet is a physical transport that can and constantly is used simultaneously for multiple different purposes with a myriad different protocols by multiple different devices hung on it. That TiVo's already using it for something else is not a valid objection--it can use it for this at the same time without strain.

Its not so much the TiVo couldn't use it, it is that it would add complexity to the TA, and to the SDV protocol, for security and multi box detection. Remember, the TA is more like a cable box than a cable modem you apparently think it is.

Its not so much the TiVo couldn't use it, it is that it would add complexity to the TA, and to the SDV protocol, for security and multi box detection. Remember, the TA is more like a cable box than a cable modem you apparently think it is.

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Since I've read the public spec from cover to cover (it's only 50 pages long, and mainly composed of API details that can be skimmed if you're not going to write code using them) and have over 10 year experience in implementing embedded network protocol stacks and applications in large scale networking equipment, I think that I may pretty well understand what it is. It's neither a cable box or a cable modem--my comment was that just about all of the hardware necessary for it is contained in a cable modem--not that it's related to a cable modem (though the spec allows it to communicate using DOCSIS protocols, if that's convenient).

It does not deal with the in-band cable signal at all--it just passes it through. An internal Y-connector would allow it to do that.

Dealing with the TA function as an IP protocol application is no more complicated than half a dozen network applications that TiVo has implemented and far less complicated than many of them.

If the TA is implemented using IP to communicate with TIVO then would it be connected to a hub in a home network and only one would be needed per home network with many TIVOs or other compatible devices?
That would save money for the cable companies and less clutter for subscribers but would introduce a single point of failure for the sub.
Maybe the next version could have USB and IP. Then subscriber could choose. If cable companies don't change for TA then I suspect they would offer subs a cheap hub instead of more than one TA.

Why do you think there will be a next version TA. Currently the only application is for an S3 or HD, although there may be some wild card TV set out there with USB ports and a cablecard slot that could be reprogrammed, if the TV set manufacturer were so inclined for such a small audience.

The next version is called Tru2Way and will be built into TV sets and the probably the Tivo S4.

I am not saying they couldn't use IP over ethernet or the home network, it is just that it would be too complex for them, or at least will add complexity they don't need. USB was just as simple and secure for them, and is the way they went.

I am not saying they couldn't use IP over ethernet or the home network, it is just that it would be too complex for them, or at least will add complexity they don't need. USB was just as simple and secure for them, and is the way they went.

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I'm highly familiar with the IP protocols and have some knowledge of USB and I'm saying that it's my highly informed opinion that it wouldn't have been any more complex. Even over USB, the Tuning Adapter performs an authentication handshake with the UDCP (i.e., TiVo) and portions of the protocol are encrypted--they wouldn't have had to do any more work to acheive that level of security in a LAN protocol nor would it have been any more complex.

In any case, what's done is done. Whether it was justified or not, they went the way that they did and we're all going to have to live with it. Not a big problem for me in my single TiVo situation, but many people, like lrhorer, have 3 or more; one guy posting in the TiVo thread at AVS Forum apparently has 7. Because of this goofy design, they're all going to have to have a big stack of these gizmos.

Since USB solution was chosen I was a little hopeful that they might be able to use USB power to the TA without need for a separate supply. Of course with ethernet solution POE could be an option, but complicates things a lot. As it turns out however the TAs still need their own power supply so I really see no advantage. I think the selection of USB was driven purely from perspective that there are many more existing A/V consumer devices out there with USB support than with ethernet support. I can't think off hand of any CableCard capable TVs with built in ethernet (there probably are some) but there are quite a few with USB. The reality is probably that very few devices (if any) other than CableCard Tivos will ever include support for these TAs so ethernet would have been a perfectly viable choice.

... Including a unidirectional CableCARD interface and a USB port in a product won't add much to its price today (TiVo includes two CableCARD slots and two USB ports in a $300 box, albeit one whose price is heavily subsidized by service contracts), and the FCC requires that nearly all television products have the ability to tune ATSC and therefore to handle decoding and imaging a reasonably high-rate MPEG-2 stream.

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but that's a $300 dollar box which is subsidized. it is not a 79 dollar tv set sold at the A&P/walmart/target for a profit.

(i'm sure at some point the price of everything drops, but just saying FOR NOW and maybe the next couple years i dont expect to see low end stuff with cablecard/usb ports.)

but that's a $300 dollar box which is subsidized. it is not a 79 dollar tv set sold at the A&P/walmart/target for a profit.

(i'm sure at some point the price of everything drops, but just saying FOR NOW and maybe the next couple years i dont expect to see low end stuff with cablecard/usb ports.)

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We have a different concept of "the low-end". No one's going to try to add interactive capabilty to a television intended to sell for $79.

I'm not saying that anyone going to actually create other TA compliant devices, but that's what the issue is--the CE OEMs arguing that they need something from the cable providers to allow them to add interactive services at a lower price-point--this presupposes a brand-new bidirectional CableCARD slot, or the coming DCAS processor, either of which I'd expect to be more expensive than the USB 2.0 port and unidirectional CC slot necessary for TA compliance, which is what the cable industry is offering as an alternative (though it will only provide SDV, when what the CE industry is asking for is cheap, fixed-function SDV+IPG+IPPV+VOD). What the CE industry is asking for, saying that they want it for low-end products, is more powerful but significantly more expensive than TA compliance, while being significantly less expensive than <tru2way> compliance.

I'm highly familiar with the IP protocols and have some knowledge of USB and I'm saying that it's my highly informed opinion that it wouldn't have been any more complex.

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I am also highly familiar with IP protocols and with USB, and your statement is correct. What's more, an Ethernet based TA would not even have had to participate in IP, at all. It could simply have been a layer 2 bridge, forwarding packets to the hardware address of the CATV host from the TiVo and to the TiVo's MAC address from the CATV host. a simple encryption layer could have been added, although I don't really see that it would have been necessary. Encryption is already in place at the application layer.